-LRB- WIRED -RRB- -- Hackers who commandeer your computer are bad enough . Now scientists worry that someday , they 'll try to take over your brain .

Scientists can use brain signals to control computers -- hands free .

In the past year , researchers have developed technology that makes it possible to use thoughts to operate a computer , maneuver a wheelchair or even use Twitter -- all without lifting a finger . But as neural devices become more complicated , and go wireless , some scientists say the risks of `` brain hacking '' should be taken seriously .

`` Neural devices are innovating at an extremely rapid rate and hold tremendous promise for the future , '' said computer security expert Tadayoshi Kohno of the University of Washington .

`` But if we do n't start paying attention to security , we 're worried that we might find ourselves in five or 10 years saying we 've made a big mistake . ''

Hackers tap into personal computers all the time . But what would happen if they focused their nefarious energy on neural devices , such as the deep-brain stimulators used to treat Parkinson 's and depression , or electrode systems for controlling prosthetic limbs ?

According to Kohno and his colleagues , who published their concerns July 1 in Neurosurgical Focus , most devices carry few security risks . But as neural engineering becomes more complex and more widespread , the potential for security breaches will mushroom .

`` It 's very hard to design complex systems that do n't have bugs , '' Kohno said . `` As these medical devices start to become more and more complicated , it gets easier and easier for people to overlook a bug that could become a very serious risk . It might border on science fiction today , but so did going to the moon 50 years ago . ''

Some might question why anyone would want to hack into someone else 's brain , but the researchers say there 's a precedent for using computers to cause neurological harm . In November 2007 and March 2008 , malicious programmers vandalized epilepsy support Web sites by putting up flashing animations , which caused seizures in some photo-sensitive patients .

`` It happened on two separate occasions , '' said computer science graduate student Tamara Denning , a co-author on the paper . `` It 's evidence that people will be malicious and try to compromise peoples ' health using computers , especially if neural devices become more widespread . ''

In some cases , patients might even want to hack into their own neural device . Unlike devices to control prosthetic limbs , which still use wires , many deep brain stimulators already rely on wireless signals . Hacking into these devices could enable patients to `` self-prescribe '' elevated moods or pain relief by increasing the activity of the brain 's reward centers .

Despite the risks , Kohno said , most new devices are n't created with security in mind . Neural engineers carefully consider the safety and reliability of new equipment , and neuroethicists focus on whether a new device fits ethical guidelines . But until now , few groups have considered how neural devices might be hijacked to perform unintended actions . This is the first time an academic paper has addressed the topic of `` neurosecurity , '' a term the group coined to describe their field .

`` The security and privacy issues somehow seem to slip by , '' Kohno said . `` I would not be surprised if most people working in this space have never thought about security . ''

Kevin Otto , a bioengineer who studies brain-machine interfaces at Purdue Universty , said he was initially skeptical of the research . `` When I first picked up the paper , I do n't know if I agreed that it was an issue . But the paper gives a very compelling argument that this is important , and that this is the time to have neural engineers collaborate with security developers . ''

It 's never too early to start thinking about security issues , said neural engineer Justin Williams of the University of Wisconsin , who was not involved in the research . But he stressed that the kinds of devices available today are not susceptible to attack , and that fear of future risks should n't impede progress in the field . `` These kinds of security issues have to proceed in lockstep with the technology , '' Williams said .

History provides plenty of examples of why it 's important to think about security before it becomes a problem , Kohno said . Perhaps the best example is the Internet , which was originally conceived as a research project and did n't take security into account .

`` Because the Internet was not originally designed with security in mind , '' the researchers wrote , `` it is incredibly challenging -- if not impossible -- to retrofit the existing Internet infrastructure to meet all of today 's security goals . '' Kohno and his colleagues hope to avoid such problems in the neural device world , by getting the community to discuss potential security problems before they become a reality .

`` The first thing is to ask ourselves is , ` Could there be a security and privacy problem ? ' '' Kohno said . `` Asking ` Is there a problem ? ' gets you 90 percent there , and that 's the most important thing . ''

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Scientists can use thoughts to operate computers , wheelchairs and Twitter

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As tech develops , risk of `` brain hacking '' become more real , scientists say

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Neurosurgical Focus article says risks are slim now

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But security `` should proceed in lockstep with the technology , '' expert says